There are many dynamics that contribute to the increasing challenge of providing enough clean water for the population that the Earth now needs to support. While the default issue is often the impacts that climate change has on watersheds across the globe, a critical element to be considered in the ongoing discussion around clean water access regards what is happening in the world’s cities. Global urban water supplies are increasingly polluted and will likely be unable to meet rapidly-growing demand.
Most of the major cities in the world have already grown too large to adequately deliver water to all their inhabitants. More than a slow motion train wreck, this is a challenge that needs to be addressed immediately as more and more people are living in urban environments where access to water is difficult or the quality of water being delivered is compromised.
A new in-depth report by The Nature Conservancy underscores the much broader global implications of rapid population growth in cities paired with unprecedented threats to their water supplies. Add to that mounting pressure on cities to take action on other environmental woes, like ill effects of climate change, and it becomes an even taller order for budget-constrained local governments.
The Nature Conservancy found that 1 in 3 of world’s 100 largest cities — which are cumulatively home to some 700 million people — are currently “water stressed.” That means water use by all sectors exceeds 40 percent of total availability from watersheds.
“Cities face twin challenges: water that is both scarce and polluted,” the report authors state. “Rising demand has been allowed to grow unchecked, competing users upstream do not talk to or trust one another, increasingly unpredictable rainfall patterns have been altered by climate change, and the watersheds where our water comes from have been degraded.”
A key challenge highlighted in The Nature Conservancy report is a history of short-sightedness when it comes to where our water is coming from.
Watersheds already in use are increasingly jeopardized by pollution, and new potential water supply options to meet increasing demand don’t look much better.
Significant deforestation has already impacted an estimated 40 percent of the hundreds of urban watersheds analyzed in the report, despite warnings from some in the water industry about resulting increases in pollutants since as far back as the 1980s.
“I was surprised seeing the trend over time,” said Robert McDonald, lead study author and The Nature Conservancy’s senior scientist for urban sustainability.
Add to that an anticipated 10 percent increase in the utilization of agricultural lands as a source for urban water by the year 2030. The use of fertilizer is projected to grow 58 percent during the same period, raising serious questions about the safety of water originating in those areas.
The report provides a wealth of information on the challenge for urban water systems and I will be posting excerpts from the report over the next few weeks.